PLANTS CULTIVATED FOR THEIR SUBTERRANEAN PARTS. 79 



he attributes pi. 51 in Rheede's Hortiis Malabaricus, vol. 

 viii., grows in damp places in the mountains of Java and 

 of Malabar. In order to put faith in these assertions, it 

 would be necessary to have carefully studied the question 

 of species from authentic specimens. 



The yam, which is most commonly cultivated in 

 the Pacific Isles under the name tibi, is the Dioscorea 

 alata of Linnaeus. The authors of the seventeenth and 

 eighteenth centuries speak of it as widely spread in 

 Tahiti, in New Guinea, in the Moluccas, etc.-^ It is 

 divided into several varieties, according to the shape of 

 the rhizome. No one pretends to have found this species 

 in a wild state, but the flora of the islands whence it 

 probably came, in particular that of Celebes and of New 

 Guinea, is as yet little known. 



Passing to America, we find there also several species 

 of this genus growing wild, in Brazil and Guiana, for 

 instance, but it seems more probable that the cultivated 

 varieties were introduced. Authors indicate but few culti- 

 vated species or varieties (Plumier one, Sloane two) and 

 few common names. The most widely spread is yam, 

 ignaTue, or inhaine, which is of African origin, according 

 to Hughes, and so also is the plant cultivated in his time 

 in Barbados.^ 



He says that the word yam means "to eat," in several 

 negro dialects on the coast of Guinea. It is true that 

 two travellers nearer to the date of the discovery of 

 America, whom Humboldt quotes,^ heard the word 

 ignaine pronounced on the American continent : Ves- 

 pucci in 1497, on the coast of Paria ; Cabral in 1.500, in 

 Brazil. According to the latter, the name was given to 

 a root of which bread was made, which would better 

 apply to the manioc, and leads me to think there must 

 be some mistake, more especially since a passage from 

 Vespucci, quoted elsewhere by Humboldt,^ shows the 



' Forstcr, Plant. Esculent., p. 56; RuTnpliius, Amhoin, vol. v., pi 

 120, 121, etc. 



^ Hughes, Hist. Nat. Barh., 1750, p. 226. 



* Humboldt, Nouvelle Espagne, 2ncl edit., vol. ii. p. 4G8. 



Ibid., p. 403. 



